If it's not what You are looking for type in the equation solver your own equation and let us solve it.
x in (-oo:+oo)
12 = (x+(3*x)/2)^2 // - (x+(3*x)/2)^2
12-(x+(3*x)/2)^2 = 0
12-1*(5/2*x)^2 = 0
12-1*(5/2*x)^2 = 0
12-25/4*x^2 = 0
12-25/4*x^2 = 0
-25/4*x^2 = -12 // : -25/4
x^2 = 48/25
x^2 = 48/25 // ^ 1/2
abs(x) = (48/25)^(1/2)
x = (48/25)^(1/2) or x = -(48/25)^(1/2)
x in { (48/25)^(1/2), -(48/25)^(1/2) }
| (36)(1*1/6) | | -5n-7(1+7n)=-8 | | 2/7(8x-7)=-4 | | 0=x^2-20x+64 | | (5-x)(x-2)=0 | | 6x-10+y=180 | | 1*1/6 | | -4x+2(-5)=-30 | | 2a-5b=-4 | | -3x+4(-3x-3)=-21-6x | | -160=-4x-4(3x+12) | | (36)(11/6) | | 5x+5(-4x+13)=185 | | 9t+-5=180 | | 6m(2+8m)= | | 8x^2-13x=3x^2-1-7x | | 2x+36=4/11x | | 4x+30=8x-10 | | 1/2d-7=6 | | 8m+3=4m-60 | | -15=x/-6-5 | | 42+1x= | | F(x)=6x^4+7x^3-12x+2 | | 12x-3=-51 | | 9x-8=5x-12 | | -y^4(-2y^3)=0 | | b(b^2)(b^3)=0 | | x/2+2=9 | | 3.4q-2.8-3.1q=0.7q-2.3 | | 24t-(1)=3+12t | | 9t-18=6t-42 | | x+4y=-22 |